Category: biogeography

Scientists and graduate students from the California Academy of Sciences have been visiting and studying the Republic of São Tomé and Príncipe for the past 17 years. This two-island nation off the West coast of Africa in the Gulf of Guinea has just revalued and redesigned its currency, the Dobra. And rather than celebrating political leaders, historical events or man-made structures and industry, the new notes illustrate what makes the islands truly special among islands of the world – their unique wildlife.

Colorful wildlife stamps are not rare of course but in this case, São Tomé and Príncipe are celebrating species unique to the islands – their endemics. The new twenty dobra note (above) celebrates the São Tomé giant tree frog, Hyperolius thomensis, largest member of its genus in the world. It is found only in the higher forests of the big island – nowhere else. The new note was fashioned directly from a photograph by Dong Lin, photographer on the first California Academy of Sciences scientific expedition to the islands in 2001.

Dong Lin, CAS photographer, F. Penny and R. Stoelting, members of the first Academy Gulf of Guinea expedition in 2001 posing the giant tree frog for the original photo below.

Hyperolius thomensis, original by D. Lin, CAS 2001]

This brilliantly colored tree frog was also the subject of the first scientific paper based on collections made by our expeditions. Since 2001 there have been 38 additional publications based on twelve more expeditions joined by more than 40 scientists and graduate students.

The 5 dobra note (top right) denotes one of two endemic (non-flying) mammals on the islands: the São Tomé shrew, Crocidura thomensis. The shrew was the subject of a 2015 publication by Dr. Ricardo de Lima of the University of Lisbon, along with three Academy colleagues. Later, another colleague, Dr. Luis Ceriaco of the Natural History Museum in Lisbon described an endemic shrew from Príncipe.
The ten, fifty and 200 dobra notes feature endemic bird species. The islands of São Tomé and Príncipe have the highest number of unique bird species in the world by unit area. This fauna has been intensively studied and brought to the world’s attention by our colleague, Dr. Martim Melo of CIBIO in Portugal. Only one bank note depicts a non-native animal – the 100 Dobra bill shows a Mona monkey, a species introduced from the mainland as a food source.

Finally, another of our colleagues who has joined us in the field and helped bring attention to the islands’ fabulous wildlife is the irrepressible Dr. Luis Mendes, famed Portuguese entomologist (above). Luis has been studying the butterflies of the islands and the African mainland for his entire career; the obverse side of each of the new Dobra notes bears an image of his butterflies (below).

Many of these lepidopterans are found on either one or the other island or both, but nowhere else in the world.
Pretty animal species frequently appear on stamps, but in the case of São Tomé and Príncipe, there is special significance. These two little islands rival the more famous Galapagos and Hawaiian islands in possessing an unexpectedly high number of unique plant and animal species, in spite of their smaller size. This would not be predicted by modern modeling nor is it yet well understood.

The new currency signifies that the people of the islands recognize that their islands’ unique environments set the country apart as truly special in the world. Clearly, the recent decade or so of field work and scientific effort has meant something to the citizens, and this is very heartening to us, the scientists who visit and seek to understand the evolution of life on “the Islands at The Center of the World”.

PARTNERSFirst, our heartfelt thanks to the citizens of the islands for allowing us and our colleagues to work among them.
Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund*.” We are grateful for ongoing governmental support from the Republic of São Tomé and Príncipe, and especially to Arlindo de Ceita Carvalho, Director General, Victor Bonfim, and Salvador Sousa Pontes of the Ministry of Environment and to Faustino de Oliviera of the Department of Forestry for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos, Anita Rodriguez and Quintino Quade of STePUP of Sao Tome, our “home away from home”. GG IX, X and XI were funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Mr. and Mrs. Henri Lese, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, in memory of Paul Davies Jr. and a heartening number of Bohemian friends. We are grateful for the support of Roça Belo Monte (Africa’s Eden-Príncipe) for both logistics and lodging.

At up to 3 m (9.8 ft) and 932 kg (2,055 lb), the leatherback is the worlds 4th largest reptile (after three crocodile species) and by far the largest turtle.

Along with two other marine species (above), the green (Chelonia mydas – inaturalist phot), and the hawksbill (Eretmochelys imbricata – Brittanica phot.), it breeds annually on certain São Tomé and Príncipe beaches.

Mouth and pharynx of Leatherback. Pinterest phot.

Leatherbacks feed almost exclusively on coelenterates (jellies or jellyfish) and swallowing them is added by long inward-pointing fleshy projections in the throat and pharynx (above). All of the worlds marine turtles are endangered species and the Gulf of Guinea Ids are important sites, guarded and studied by a number of NGO’s including the Príncipe Trust and ATM: the Association for the Protection, Research and Conservation of Sea Turtles in Lusophone countries.

The birds (avifauna) of the two islands are quite remarkable. Combined, São Tomé and Príncipe are only about 1000 km² and yet they are home to 28 unique endemic bird species of many different families. This is the highest density of bird endemism by area in the world. We have also discussed gigantism and dwarfism (above), poorly understood phenomena occurring frequently in island plants and animals.

São Tomé Grosbeak, Neospiza concolor, M. Melo phot and at right.

There have been several recent studies on the islands’ endemic bird species. Dr. Martim Melo of CIBIO, foremost latter-day student of this avifauna has shown that the genetic relationships of the seemingly extremely scarce São Tomé Grosbeak (above) reveal that it is actually a canary, not a grosbeak. It is thus now the world’s largest canary and a true island giant. It is 50% heavier than the next largest related species. As an island giant, it joins other São Tomé giant endemics like the Giant Sunbird, Dreptes thomensis, and the Giant Weave,r Ploceus grandis, the two largest species of their families in the world. These have been featured in earlier blogs. Two additional, less famous São Tomé species are the largest species of their respective families in Africa (above).

São Tomé Speirops, Xosterops lugubris. Phot. Lars Petersson]

SãoTomé Thrush, Turdus olivaceofuscus, Phot. Lars Petersson]

Under different systems, all of the endemic bird species could be considered rare and endangered since each unique species can only have a range of significantly less than 1000 km², which is the area of the two islands combined. In a sense, these unique species could be considered among the rarest in the world. One of the fathers of the “modern synthesis” (evolution + genetics), Prof. Ernst Mayr, wrote a paper in the magazine Science examining the levels of bird endemicity in relationship to island size and distance to mainland source. The extraordinary density of the endemic birds of our islands when compared with predicted levels (below) yield a separate third curve; a phenomenon he simply illustrated but with no attempt to explain it.

The status of nine of the São Tomé endemics is “threatened” according to modern ornithologists; until recently, three of these have been considered “critically endangered”: the São Tomé Grosbeak (above), the Dwarf Olive Ibis and the São Tomé Fiscal Shrike (below)

São Tomé Fiscal Shrike, Lanius newtoni. Phot. L. Petersson

Dwarf Olive Ibis, Bostrychia bocagei. Phot. L. Petersson

A recent paper by Dr. Ricardo de Lima (below) and colleagues is an examination of the ranges and population status of these three endemic birds. They found that the south-west central region of the island, most of which is included in the São Tomé Obô Natural Park, has the highest potential for the Critically Endangered birds, and that indeed all three species were associated with native forest. The ibis prefers high tree density, while the fiscal selects low tree density and intermediate altitudes. “Despite very restricted ranges, population sizes seem to be larger than previously assumed. These results suggest that the fiscal and grosbeak might be better classified as ‘Endangered’, while the ibis should maintain its status under different criteria, due to a very restricted range during the breeding season.”

The colorful and varied endemic bird fauna of São Tomé and Príncipe is a flamboyant if somewhat enigmatic example of speciation and evolution over time. As the graph above illustrates, there are more endemic species by unit area than one would predict, even in light of the near proximity of the African mainland. Although the unique species are now reasonable well-described compared with other elements of the fauna, there is still a great deal to be learned.

The only venomous snake on the islands is the Forest Cobra “Cobra preta”, of São Tomé, fairly common in most inland habitats, and the source of some controversy over the years (see blog, May 2009). Whether it is naturally occurring i.e., the descendent of a disperser like many of the terrestrial uniques, or whether it was brought by man in some manner has been a point of discussion for some years. For a long time the few scientists working on the islands have referred to this species as Naja melanoleuca, a large cobra which is widespread on the African mainland (below).

From blog, May 2008: Within the House of Slytherin II. (left) Naja melanoleuca. Cowyeow photo]

A recent publication by Dr. Luis Ceríaco et al. (National Museum of Natural History and Science) suggests that the São Tomé cobra is a naturally occurring endemic; they have named it Naja peroescobari, after one of the Portuguese navigators who discovered the island in 1471. The authors distinguish Cobra preta from the mainland species by slightly larger size, a different color pattern underneath, and the arrangement of some scales in the throat area.

While on the subject of reptiles, recent expeditions have afforded us with more knowledge, along with some outstanding new photos of related island endemics:

São Tomé “jita”. Boaedon (Lamprophis sp). Phot Lars Petersson

Príncipe “jita”. Boaedon (Lamprophis sp). Phot. Andrew Stanbridge

We know these two island species are distinct from one another and from close mainland relatives on the basis of pattern and molecular evidence. The big island species (above) has a pattern of lines along the back; that of Príncipe is a series of blotches. A group of us led by Dr. Luis Ceríaco is in the process of assigning new names to these island two populations.

Hugulay Maia (insert, below) is a young São Toméan from the big island who has been interested in the natural history of the Gulf of Guinea Islands for most of his life. He and his mentor, the late Angus Gascoigne, have appeared in this blog a number of times over the years, and Hugulay is currently a PhD candidate in marine ecology at the University of Santa Catarina in Brazil. He has just produced a durable guide to the marine species most frequently encountered by local fishermen, pictured below. As a scientist he will be a strong, valuable asset to the islands’ fauna and flora and to the government, especially with respect to the conservation of its natural marine resources.

Quade of STeP UP has been a bulwark of our field work and education program since the beginning in 2001. He is a translator, teacher of English and many other useful things. Chase is a consultant from Washington D.C., examining possibilities for expansion and modification of our Gulf of Guinea Project in the future.

The Parting Shot:

Me at Jockey’s Bonnet, Principe Id. This is an ancient island off the east coast that harbors a currently recognized endemic subspecies of finch.

PARTNERS
Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund*.” We are grateful for ongoing governmental support from the Republic of São Tomé and Príncipe, and especially to Arlindo de Ceita Carvalho, Director General, Victor Bonfim, and Salvador Sousa Pontes of the Ministry of Environment and to Faustino de Oliviera of the Department of Forestry for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos, Anita Rodriguez and Quintino Quade of STePUP of Sao Tome, our “home away from home”. GG IX, X and XI were funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Mr. and Mrs. Henri Lese, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, in memory of Paul Davies Jr. and a heartening number of Bohemian friends. We are grateful for the support of Roça Belo Monte (Africa’s Eden-Príncipe) for both logistics and lodging.
*55 Music Concourse Drive, Golden Gate Park, San Francisco CA 94118 USA

The scientific name of each living species is like the handle on a drawer, enabling biologists to pull it open and learn all that has been observed and written about that species. These names, usually Latinized or in Greek, are the most basic building blocks in any attempt to describe the Earth’s natural habitats and ecological systems… literally the first step in the exploration of unknown or poorly known habitats. First question asked: what’s living there? If no one has noted a species before, we communicate its existence by describing it and giving it a name..

Our first expedition to the islands of São Tomé and Principe was in 2001, and the first new island species our scientists described was a beetle (below). Although it was collected high in the mountains on São Tomé during our first expedition, the new name was actually published four years later.

Straneo seligmani Kavanaugh, a new carabid beetle from near Macambrara, São Tomé at about 1100 m. Straneo is an endemic genus; its two known species occur only on this island..

It takes a lot of time to recognize and describe a new species; after all, the scientist has to know all of related species that the new species is not! This new beetle was named for Ned Seligman, Director of STeP UP, an island NGO. We have worked closely with STeP UP since the beginning in 2001.

Another special insect collected on our first expedition was an ant species new to science; it was described a few years later (below).

Tetramorium renae Garcia, Fischer & Peters from Bom Sucesso, São Tomé

During the past 17 years, our teams have undoubtedly collected many new insect species on São Tomé and Príncipe. But it takes a lot of time for entomologists to sort through our nearly two decades of island specimens.

The bryophyte flora (mosses, liverworts and hornworts) was poorly known before tireless Jim Shevock joined us on several recent expeditions. The new moss species described by Jim and his colleagues (below) is but the first of many awaiting publication.

Porotrichium saotomense Enroth & Shevock from São Tomé

In fact, Jim and his colleagues such as Dr. Cesar Garcia the University of Lisbon (above) have added 46 mosses, 66 liverworts and 3 hornworts to the flora of the islands so far, suggesting that this group is surprisingly rich these ancient islands .

Botanists at work on Príncipe, GG XI. A. Stanbridge phot.]

Lizards are usually a fairly conspicuous part of any environment during both day and night (geckos), so it might be expected that the lizard fauna of the two islands would be well known. Not so; our teams have described one new species and are working on a second.

Principe, 2008

Hemidactylus principensis Miller, Sellas & Drewes. Weckerphoto.

This nocturnal gecko of Príncipe Island shares a unique character with its nearest relative, H. greeffii of São Tomé – the absence of the last digit on the thumb (below).

An additional new species was described a couple of years ago by Dr. Luis Ceriaco of the University of Lisbon. The skink lives on Tinhosa Grande, an islet off the south coast of Principe.

Trachylepis adamastor Ceriaco, Tinhosa Grande island.

Several earlier blogs have featured our mushroom work ; in earlier times, there were only about twelve known species on the islands. Drs Dennis Desjardin and Brian Perry collected more than 200 kinds during GG II and III expeditions, and their analysis of these specimens is ongoing.

The description of Phallus drewesi Desjardin & Perry (above) was the first of the new mushroom descriptions and for obvious reasons, its shape and size received some notoriety- it is the second smallest mushroom in the genus Phallus, and it grows limp. The publication was featured on a humorous American radio show called “Wait, Wait. Don’t Tell Me!”

Scytinopogon havencampii Desjardin & Perry of Principe (above) was named in honor of a group of friends who helped fund this particular work. Earlier this year, four additional new species from both islands were described by Desjardin & Perry and just this week, the same authors published yet another scientific paper in the international journal, Mycosphere. They recognized 31 hitherto unreported fungus species on the islands, and these include ten new ones; three of the new species names commemorate individuals who have helped support our expeditions: Campanella burkeii, Gymnopus rodhallii and G. billbowesii.

Campanella burkei Desjardin & Perry from Principe Island.

Gymnopus rodhallii Desjardin & Perry from São Tomé.

Several of our expeditions have included workers studying inshore marine organisms. Then graduate student Dana Carrison-Stone published the descriptions of two new species of barnacles she discovered during dives in 2008 (GG III).

Conopea saotomensis Carrison-Stone, Van Syoc, Williams & Simison. The other new species, C. fidelis, was described in the same publication. Both were collected off Príncipe Island and formed part of the research for her MSc degree]

Carrison-Stone in the field off Príncipe, GG III

Drs Tomio Iwamoto and Luis Rocha have both worked on our Gulf of Guinea expeditions, Tomio since the very beginning in 2001. Luis has led several separate diving expeditions there including GG X in 2016 .

Serranus pulcher Wirtz & Iwamoto (above) was described from a specimen Tomio caught by rod and reel off the pier of Ned Seligman’s house on the northeastern shore of São Tomé during GG II. Luis named Sparisoma choati Rocha, Brito & Robertson (below), a new parrotfish from the waters of Príncipe just last year (Rocha phot).

Amphibians are not supposed to occur on islands that have never been attached to a mainland source. This point has been made about oceanic islands ever since islands have been studied (see early blogs in this series); for obvious reasons (salt water) the same is true for freshwater fishes. Nevertheless, São Tomé may well be unique in having eight species of endemic amphibians, two of which were discovered and described by members of our Gulf of Guinea expeditions.

Phrynobatrachus leveleve Uyeda, Drewes & Zimkus of São Tomé (above) was discovered to be genetically distinct from its Príncipe relative, P. dispar as early as 2007 by Dr. Josef Uyeda, a two-time expedition member.

A similar situation exists with the very similar small green tree frogs of the islands. Dr. Rayna Bell discovered that the two island populations were actually quite distinct from one another and named the Príncipe species, Hyperolius drewesi Bell, a great honor.

Hyperolius drewesii Bell of Príncipe. Gasparini phot.

Finally another graduate student contributor to our island work on São Tomé and Príncipe is Matthias Neumann of the University of Kassel, Germany. His fieldwork on flatworms (aka geoplanids) of the islands led to the description of five new species in a recent publication. His work is particularly relevant as many of these strange, brightly colored species are known predators of land snails, and the snail species of São Tomé and Príncipe are more than 70%endemic, found nowhere else in the world.

Various geoplanid flatworms from São Tomé among which are five new species described by Sluys and Neumann.

We will be returning to the islands once again in November.

Here’s the Parting Shot:

Rio Porco, at the remote southern end of Príncipe not far from new Scops owl species site (see last blog). A. Stanbridge phot.

PARTNERS

Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund*.” We are grateful for ongoing governmental support from the Republic of São Tomé and Príncipe, and especially to Arlindo de Ceita Carvalho, Director General, Victor Bonfim, and Salvador Sousa Pontes of the Ministry of Environment and to Faustino de Oliviera of the Department of Forestry for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos, Anita Rodriguez and Quintino Quade of STePUP of Sao Tome, our “home away from home”. GG IX, X and XI were funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Mr. and Mrs. Henri Lese, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, in memory of Paul Davies Jr. and a heartening number of Bohemian friends. We are grateful for the support of Roça Belo Monte (Africa’s Eden-Príncipe) for both logistics and lodging.

Note: This blog and the preceding one are dedicated to the memory of our friend Bill Bowes, of the William K. Bowes Jr. Foundation, who graciously lent his personal encouragement to and support for the GG IX, X and XI expeditions. We of the Gulf of Guinea team and the California Academy of Sciences will miss him very, very much.

The São Tomé weaver (Ploceus sanctithomae] is a forest species known only from the big island. Phot. P. Loureiro.
During Gulf of Guinea IX, two years ago, our education effort was focused on the endemic bird species of both islands; as mentioned before, the bird fauna is hugely important; the two islands have perhaps the highest number of unique bird species by area in the world, 28 endemics/1000km ².

The São Tomé Prinia. (Prinia molleri). The “Truqui” is found only on the big island and is probably the most common endemic species there (top photo. P. Loureiro.) As we visited the classrooms, each student got a pair of plastic binoculars (they work!), and our booklet that highlights some of the most beautiful species on both islands and their natural history (above, left and right. phots by A. Stanbridge).

And, expedition patches are given by the teachers to 10 students who do the best work each year. (photo by A. Stanbridge, above)

Our intent is always to instill in the kids a sense of ownership for these species for their uniqueness and beauty: “No one else has these, even on the other island!” The image below was taken by our senior educator, Roberta Ayres, but it might have been made anywhere little kids play. Regardless, we never preach in our classroom presentations; we present the species of the flora and fauna as rare and beautiful.

Our Gulf of Guinea Islands project is indeed multiplex, and some of the most interesting scientific discoveries in past years have been made by graduate students in pursuit of higher degrees.

Recently, Ana P. Coelho (above middle), received her MSc degree in conservation biology from the University of Lisbon; her thesis advisor was our long-time colleague, Dr. Ricardo Lima (left), whose earlier PhD thesis was also based on the island ecology.

Field assistant Octavio, mist-nettng (A. Coelho phot.)
Ana studied the roles of birds in dispersing seeds on São Tomé. Some 18 species of birds, all endemic, were systematically mist-netted (above), and ring-banded (below). Their droppings were studied over time to determine what seeds the fruit-eating (frugivorous) species were eating. The field/data collection part of the study was several months in duration.

Of the 18 species captured and released, nine were frugivorous, and Ana showed that the great majority of seeds they ate were in the fruit of endemic or native plant species. Some species of non-native plants were ingested and dispersed as well.

This relationship among endemics makes evolutionary sense. We know that the accumulation of genetic (and morphological) change leading to the evolution of new species takes isolation and time. This is as true for the consumer (the birds) as it is for the energy source (the fruit of the plants). So one can suggest that the birds and the seed plants upon which they feed co-evolved over thousands of years. The birds benefit from the fruits of the plants and in turn, the plants’ seeds are carried to distant environments (along with fertilizer) in the bird droppings.

The São Tomé speirops (above) is by far the most frequent seed disperser; Ana found this endemic produced 84% of all droppings containing seeds. .

However, it should be noted that in this case, the birds are also responsible for a rather difficult conservation issue. Through seed dispersal of endemic plants, they are contributing to native forest regeneration, but because they also disperse a number of non-native plant species, the birds are also involved in biological invasion – the spread of alien species..

Above is an additional endemic predator/prey relationship: a São Tomé house snake ingesting a São Tomé giant tree frog; both species are endemic to the big island. (Matthias Neumann phot. )

Another recent graduate student contributor to our scientific knowledge of Gulf of Guinea biology is Matthias Neumann (below), who recently completed his MSc in biology at the University of Kassel in Germany.

(M. Neumann phot)

Matthias spent a couple of months in the islands last year collecting and studying geoclads (flatworms), many species of which are known to be predatory on snails.
We have made the point in earlier blogs that these flatworms are potentially very important because the land snail fauna of both islands is over 70% unique, and if these flatworms are recent arrivals, they may pose a real danger to the existence of the endemic snails. Prior to Matthias’ field investigations almost nothing was known about the island flatworm fauna except for some random observations by some of us working in the forests (see earlier blogs).

Mathias (left) with field assistant, Lionel; a geoclad feeding on a terrestrial snail (right). M. Neumann phots.
Matthias was successful in completing his degree, and his work has recently been published: Sluys R., M. Neumann, R.F. de Lima, & R, C. Drewes. 2017. Land flatworms (Platyhelminthes, Geoplanidae) of São Tomé: a first account on their diversity, with the description of five new species. Zootaxa 4221 (3): 291–322.

Matthias estimates that there at least as many additional undescribed flatworm species on the islands awaiting identification and study. Two of the species he has discovered so far are definitely snail predators. If these two species are long-time inhabitants of the islands, it is likely they have co-evolved with their snail prey, a situation probably not unlike the endemic bird/endemic plant relationship studied by Ana Coelho. There is so much more to be learned in these islands.

As Ana’s and Matthias’s photos above suggest, both of these young scholars are born naturalists, interested in a wide range of living species. The images include a freshwater blenny, a freshwater shrimp, a São Tomé house snake and a giant sunbird, all endemic or native to the islands.

The Parting Shot:

Dr. Cesar Garcia, of Lisbon, working on Principe. Fieldwork is always exhausting, occasionally painful but forever a joy!
PARTNERS
Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund*.” We are grateful for ongoing governmental support from the Republic of São Tomé and Príncipe, and especially to Arlindo de Ceita Carvalho, Director General, Victor Bonfim, and Salvador Sousa Pontes of the Ministry of Environment and to Faustino de Oliviera of the Department of Forestry for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos and Quintino Quade of STePUP of Sao Tome, our “home away from home”. GG IX, X and XI have been funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Mr. and Mrs. Henri Lese, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, in memory of Paul Davies Jr. and a heartening number of Bohemian friends. We are grateful for the support of the Omali Lodge (HBD-São Tomé) and Roça Belo Monte (Africa’s Eden-Príncipe) for both logistics and lodging.
*California Academy of Sciences
55 Music Concourse Dr.
San Francisco, CA 94118

Principe Island looking south toward Rio Porco, site of the new discovery. A. Stanbridge phot.

The birds of São Tomé and Príncipe are truly spectacular and by rights should be a major birdwatchers tourist destination. The island avifauna is probably the best understood of the terrestrial vertebrates and since our research concentrates on poorly known species, our expeditions have never included an ornithologist and the incredible bird life appears only occasionally in this blog. Recent events require further attention.

Birds have fascinated amateurs and scientists alike from very early on in the history of science; because of this strong and enduring attention, the discovery of new, undescribed bird species is rather infrequent and thus quite exciting.

The Principe scops owl, valley of the Rio Porco. phot P. Verbelen

After some 90 years of rumors and speculation, Felipe Spina of Fauna & Flora in Santo Antonio and Philippe Verbelen of Belgium discovered there is, in fact, an owl species living on Príncipe Island! It has finally been seen, photographed (above) and recorded by these gentlemen in the remote southern valley of the Rio Porco, in July, 2016.

Scientists know very little about the new owl beyond discovery that it exists. We do know that the call of the little owl is very different from the call of other known scops species.

The Sao Tome scops owl, Otus hartlaubi. Phot. Hotspot Birding.

But how many owls are there in these rugged, trail-less valleys, and how widely are they distributed on the island? Is it really a new species, genetically distinct from the nearby São Tomé scops owl, Otus hartlaubi? (above) There are three widely distributed species on the mainland, plus two found exclusively in different East African coastal forests (below), and there is another island endemic in the Indian Ocean (Socotra).

Sokoke scops owl, known only from the Arabuko-Sokoke Forest of coastal Kenya. phot. of red phase by Syczek Brunatny.]

How do the Gulf species relate to other scops owls? These basic questions can only be answered by detailed genetic and morphological examination of a live specimen; future work is being planned and led by Dr. Martim Melo of CIBIO, Porto, Portugal, the foremost expert on the birds of São Tomé and Príncipe. Martim first heard this owlet in 1998 and has been searching for it ever since!

The non-wading bird assemblage of São Tomé and Príncipe may represent the highest level of unique species in the world, by area. Above is an image comparing the bird faunas of the two Gulf islands with the famous Galapagos, a much larger archipelago in the Atlantic Ocean. The Galapagos are justly famous, but it is interesting to note that the majority of endemic bird species there evolved from a very few colonizers; for instance, the celebrated Darwin’s finches are all each others’ closest relatives.

The São Tomé and Príncipe avifauna is much richer in different evolutionary lineages; these range from endemic starlings (above), weavers and an oriole to unique sunbirds, kingfishers and flycatchers.

Sao Tome giant weaver. Phot by. Nik Borrow

Among this rich assemblage are several species that are excellent examples of the phenomena of island gigantism and dwarfism discussed in earlier blogs. For instance, the largest weaver bird in the world (70+ species) is the giant weaver (Ploceus grandis, above), endemic to São Tomé. The world’s largest sunbird (Dreptes thomensis, below) is a species also unique to São Tomé.

Sao Tome giant subird. phot. Fabio Olmos

Sunbirds are Old World, nectar-feeding equivalents of the New World hummingbirds. The two groups are not closely related, but they converge greatly in appearance and behavior because they fill the same ecological niche in their respective geographic areas.

Above, the giant sunbird is shown on the right, together with Newton’s sunbird, itself an endemic species; photo taken after banding by Dr. Martim Melo. Like the giant hummingbird of the Andes, the giant hummingbird is also drab in coloration.

São Tomé dwarf ibis. phot. Nik Borrow

There are 27 species of ibis, world-wide; the smallest by far is the São Tomé dwarf ibis, (above, Bostrychia bocagei); there is but a single population of these birds living in the remote southern forest of the big island, and they are severely threatened by poaching for food and the expansion of a large oil palm plantation to the south.

Many of the unique birds on the two islands are singletons; i.e. they are the only representative of their group on one of the two islands, with no relatives on the other.

São Tomé oriole, Oriolus crassirostris.

These endemic flycatchers are also sexually dimorphic]

Among the other endemic species are pairs represented by one closely related species on each island. When these species are each other’s closest relatives, they are called “sibling species; however, they can be very similar in appearance and behavior because they fill the same ecological niche on each island- not because they are each others’ closest relatives.

Each island has a thrush species; the Principe thrush (right), newly discovered, is obviously similar and related to that of the big island, but they are not necessarily each others’ closest relatives. Dr. Melo has determined by genetic study that their ancestral colonizers arrived at very different times from the mainland. Recall that Principe is geologically twice as old as Sao Tome. If the ancestor of the thrush on Sao Tome dispersed from Principe, they would be siblings, but as Dr. Melo has shown, both species descended from mainland ancestors at different times.

Many other intriguing bird pairs are found on the islands.

A number of much earlier workers considered some of the islands’ bird species so distinct that they deserved their own generic names, and traditionally, there were seven unique genera recognized on the islands (including the giant sunbird, and Speirops, above). Dr. Melo has shown that even though some of these are dramatically different in appearance from relatives, this similarity is the result of relatively recent selection pressures and genetically, they should still be included within pre-existing genera.

Note: This blog, Part II to follow, is dedicated to the memory of our friend Bill Bowes, of the William K. Bowes Jr. Foundation, who graciously lent his personal encouragement and financial support to and for the GG IX, X and XI expeditions. We of the Gulf of Guinea team and the California Academy of Sciences will miss him very, very much.

THE RACE: At Play in the Fields of a “Lost World”

“Jita,”the Principe house snake (above, Lamprophis); the Sao Tome form is striped, not blotched. They are different species from each other and from mainland relatives, and we are in the process of describing them.

As I began to write this, Drs Lauren Esposito and Rayna Bell were spending their second rain-drenched night camping in the rugged southern end of Príncipe, accompanied by biologist Felipe Spina of the Príncipe Trust and local guide, Balô. Like the botanists a week and a half ago, they traveled by boat (there are no roads in the southern two-thirds of the island) to the Rio Porco, which drains an isolated valley where a likely new species of Scops owl was recently discovered by Felipe. It had been pouring rain since they left, and we had just learned (by lucky text) that they proceeded to the top of Pico Mesa! So for the first time ever, we have had two different teams exploring this remote and difficult “lost world” on Príncipe Island. The team has since returned, safe and sound, and we are now back on São Tomé-the big island

The Belo Monte boat; Pico Mesa in the background.

Left, Filipe Spina, Principe Trust biologist with Rayna Bell.

Lauren is a relatively new Academy faculty member of our Entomology Department who specializes on the biology of scorpions. But given that only one species has ever been recorded here (by us on São Tomé in 2001), she is donning the cloak of general arachnologist, sampling spiders, amblypigids and other poorly known island invertebrate faunas. She thus joins the ranks of earlier expedition members such as Drs. Charles Griswold, Joel Ledford, and Tamas Szuts of Hungary.

Latrodectus

Heteropoda

Leptopholcus

Above is Isometrus, the only scorpion species known from the island; this specimen is from the basalt cliffs of the northwestern part of the island. Scorpions glow under ultraviolet light. Lauren has also been very involved with our education project; she brings the experience of having founded and continues to run an extensive similar program in the West Indies.

Rayna Bell (above) has returned as a team member for the fifth time. After completing her postdoctoral appointment at the University of California, she became the new curator of herpetology at the Smithsonian Institution, our U.S. National Museum.

Among her recent discoveries is that the green tree frog of Príncipe (above) is quite different from its similar counterpart on São Tomé; the scientific description will be published this month and will bring the amphibian biodiversity of the islands to eight endemic species! Rayna is also studying development (egg mass below)

The new green tree from of Principe Island.

.Dr. Bell is currently working on understanding more about the biology of the enigmatic Príncipe giant tree frog, Leptopelis palmatus. Prior to our 2001 expedition this largest of African tree frogs was known only from a single female specimen collected over 100 years ago. During our first work on Príncipe, we were able to collect and describe the much smaller males of this species but even to this day, the larvae (tadpoles) remain unknown. As can be seen above, the highly variable colors and patterns in this species are very unusual; they exhibits a high level of color and pattern polymorphism. The reason for this is unclear; in such cases, this variation is usuall due to natural selection for crypsis (camouflage), mate recognition or sexual dichromatism. We have no evidence that the frogs are particularly distasteful or toxic to predators; i.e., warning or “aposematic” coloration.

Also, adult tree frogs of this species appear to attain sexual maturity at varying sizes; reproductively mature males and females on the mainland usually attain a fairly narrow range of size. Early indications suggest this is probably not the case with the giant tree frog of Príncipe, where mature females appear to vary in size within 20-30mm.

Maria Adelina Jeronimo has returned with us for her second expedition, having completed all but her thesis defense for her PhD at the New University of Lisbon (Gulbenkian Institution). She is an expert on butterfly genetics, and particularly interested in environmental influences upon gene expression. In GG IX, she worked with Dr. Luis Mendes specimens to support his monograph of the island lepidoptera.

Lauren and Maria (right) working at night on Sao Tome.

Most of Maria’s specimens (below) must be examined in the laboratory before they can be postively identified.

Eurema hecabe

In addition to continuing to sample butterfly and moth species in the field, she has been closely involved the production and presentation of our primary school biodiversity awareness program. As readers already know, this program annually reaches around 2,000 third, fourth or fifth grade students in different schools on both islands.

As a last project, the team went south on Sao Tome into the habitat of the endemic ibis, the Galinhola. This endemic is the smallest ibis in the world and is highly endangered by habitat loss and hunters seeking bush meat. And below is the endemic gecko, Hemidactylus greeffi, found only on Sao Tome

Ex Africa Semper Aliquid Novi; indeed, there is always something new out of Africa.I have just learned that Drs Dennis Desjardin and Brian Perry just published the 4th scientific paper based on their collections made on Sao Tome and Principe much earlier (Gulf of Guinea expeditions II and III).

To date, they have added 25 new species records for the two islands and described six unique, endemicss. There is a great deal of material yet to be examined; they estimate there are many more undescribed fungi in the collection.Here’s the Parting Shot:

Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund.”* On the islands, we are grateful for ongoing governmental support, and especially to Arlindo de Ceita Carvalho, Director General of the Ministry of the Environment and Faustino de Oliviera of the Forestry Department, Republic of São Tomé and Príncipe, for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos and Quintino Quade of STePUP of Sao Tome, our “home away from home”. Gulf of Guinea XI has been funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Timothy M. Muller, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, and a heartening number of “Coolies”. Once again we are deeply grateful for the support of the Omali Lodge (HBD-São Tomé) and Roça Belo Monte (Africa’s Eden-Príncipe) for both logistics and lodging, and to the Príncipe Trust for partial sponsorship of the production of our primary school, biodiversity awareness education program.

THE RACE: Our Botanists “Run The Table”

Gulf of Guinea Expedition XI is now at the midpoint. When we arrived two weeks ago, one team stayed on the big island while our botany group proceeded almost immediately to Principe, the smaller and most ancient in the archipelago (31 myr). Two of the botanist only had a couple of weeks, and the team was entering highly inaccessible parts of the southern half of the island for the first time. The title of this blog refers to Pico Mesa (table), the most arduous and final botany destination of GG XI.

I have decided to construct this blog report as a series of Andrew Stanbridge’s magnificent photos made during expeditions into four rather remote parts of Principe Island. The botanists were introduced in an earlier blog.

I. Day hike into Morro De Leste in the Obo National Park. A relatively easy access point into primary forest in the northwest corner of the island.

Jim Shevock (California Academy of Sciences)

Dr. Tom Daniel (California Academy of Sciences)

II. Praia Seca to Rio Porco. A beach on the extreme south coast of Principe and hike to the ridge overlooking the Rio Porco (overnight). There are no roads here, and the southern reaches of the island must be accessed by boat. The botanists joined a group researchers and trainees from the Principe Trust that was searching for individuals of the recently discovered Principe scops owl and teaching forest mapping techniques to local participants.

Traveling down the east side of the island in a boat from Belo Monte.

Dr. Cesar Garcia of the University of Lisbon. Cesar is a specialist in bryophytes: mosses, liverworts and hornworts, as is Jim Shevock of CAS.

III. A day expedition on the north coast-Military Caverns to Praia Banana

Below: Balo demonstrates how to stay hydrated using the jungle’s resources

Below: Dr. Shevock collects his 50,000th career sample!

All of the botanists returned home at time of writing. The next posting will be on the various activities of the remaining six expedition members.

PARTING SHOT:

Straw-colored fruit bat (Eidolon helvum) Photo: Cesar Garcia

PARTNERS

Our research and educational expeditions are supported by tax-deductable donations to the “California Academy of Sciences Gulf of Guinea Fund.”* On the islands, we are grateful for ongoing governmental support, and especially to Arlindo de Ceita Carvalho, Director General, Victor Bonfim, and Salvador Sousa Pontes of the Ministry of Environment of the Republic of São Tomé and Príncipe for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos and Quintino Quade of STePUP of Sao Tome, our “home away from home”. The upcoming GG XI has been funded in part by a generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Rod C. M. Hall, Timothy M. Muller, Mr. and Mrs. John L. Sullivan Jr., Mr. and Mrs. John Sears, and a heartening number of “Coolies”. Once again we are deeply grateful for the support of the Omali Lodge (São Tomé) and Roça Belo Monte (Príncipe) for both logistics and lodging, and to the Príncipe Trust for partial sponsorship of our ongoing primary school education program.